JP2016102378A - Construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction machine capable of performing air bleeding on cooling water passages provided at a radiator and an engine.SOLUTION: A construction machine comprises: a cooling fan 10 that is disposed between a radiator 30 and an engine 9 and sends air taken in through the radiator 30 to the engine 9; and a shroud 11 that is provided on the outer peripheral side of the cooling fan 10 to form a passage for air taken in through the radiator 30. The construction machine also comprises: a tank 12 that stores cooling water to be supplied to the radiator 30 and the engine 9 and is disposed above the top end part of the radiator 30; and a cover attached to an aperture provided on a top surface plate 11B of the shroud 11 so that the cover is capable of being opened/closed. The tank 12 is disposed at a position adjacent to the shroud 11 and on the engine 9 side from the cover.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a construction machine including a tank in which engine cooling water is stored.

  As a background art document of the present invention, there is JP-A-11-190046. In this document, in a hydraulic excavator in which an engine, a cooling fan connected to the engine, and a radiator arranged in front of the cooling fan are housed in an upper swing body, a reserve tank ( (Reservoir tank) is placed directly above the shroud of the cooling fan, the water inlet of the reserve tank and the water inlet of the radiator are arranged at almost the same height, and both water inlets are connected to each other by a hose. Is described.

Japanese Patent Laid-Open No. 11-190046

  The engine cooling system of the above document has a reserve tank open to the atmosphere, and exchanges cooling water with the reserve tank via a water injection port (water injection cap) provided in the upper part of the upper tank of the radiator. Only a hose for exchanging cooling water with the radiator is connected to the unit. This type of system requires that the reserve tank must be installed at a location below the height of the radiator fill cap to prevent coolant from flowing out of the reserve tank when the radiator fill cap is opened. However, since there are a relatively large number of spaces in the excavator that satisfy the condition, it is relatively easy to satisfy the condition. For example, there is a hydraulic excavator that stores a reserve tank in a place where a side surface of an upper revolving body provided with an intake port for cooling air is opened.

  On the other hand, in recent years, it has become easy to accumulate air in the cooling water flow path because of an increase in the length of the cooling water flow path in the engine, and air is vented not only from the radiator but also from the cooling water flow path of the engine. There is a growing need. Therefore, one end of an air vent pipe for removing air is connected to the cooling water flow path of the engine, and the other end is connected to an air layer in a closed type reserve tank (sometimes called an expansion tank), The use of a cooling system that supplies water so that only the cooling water is returned to the cooling water flow path after the gas-liquid separation of the cooling water in the reserve tank has been started. In an engine cooling system equipped with this type of air vent pipe, the position of the reserve tank must be set higher than the water level of the flow path arranged at the highest position among the cooling water flow paths configured in the radiator and the engine. There is. However, in the conventional upper swing body of a hydraulic excavator, there is often an engine cover directly above the radiator, and it is difficult to secure a storage space for the reserve tank here. If the bottom area (cross-sectional area) is increased, the reserve tank height can be kept low. However, if the bottom area is too large, water supply from the reserve tank becomes impossible when the excavator works on a sloping ground. Therefore, it is necessary to secure a certain height for the reserve tank.

  In addition, the review of the engine cooling system requires not only the items that need to be newly examined as described above, but also the items that had not been considered before. For example, because an air vent pipe is connected to the upper part of the upper tank of the radiator, it is necessary to secure another water supply route that does not impair the water supply performance instead of the conventional method of supplying water to the upper tank. Furthermore, when deciding where to install the reserve tank, care must be taken to ensure that there is a space where a blower (blower) can be inserted between the radiator and the cooling fan for cleaning the radiator.

  An object of the present invention is to provide a construction machine capable of bleeding air from a cooling water flow path provided in a radiator and an engine.

The present application includes a plurality of means for solving the above-described problems. For example, an engine, a radiator that cools the cooling water heated by the engine by heat exchange, and the radiator and the engine are provided. A construction machine comprising: a cooling fan that is disposed on the cooling fan that sends air taken in via the radiator to the engine; and a shroud that is provided on the outer peripheral side of the cooling fan and that forms a passage for the air taken in via the radiator A tank that stores cooling water supplied to the radiator and the engine, and that is disposed above the upper end of the radiator, and a cover that is openably and closably attached to an opening provided on the upper surface of the shroud. The tank is disposed adjacent to the shroud and closer to the engine than the cover. Construction machine according to claim.
It is characterized by.

  ADVANTAGE OF THE INVENTION According to this invention, the air bleeding in the cooling water flow path provided in a radiator and an engine is attained, without impairing the water injection performance to an engine cooling system, or the cleaning performance of a radiator.

1 is a side view of a hydraulic excavator 1 according to an embodiment of the present invention. FIG. 3 is a top view of the upper swing body 4 in the hydraulic excavator 1. FIG. 3 is a schematic cross-sectional view of the upper swing body 4 in the III-III cross section in FIG. 2. 1 is a schematic configuration diagram of an engine cooling system provided in a hydraulic excavator 1. FIG. FIG. 5 is a schematic cross-sectional view of the upper swing body 4 in the VV cross section in FIG. 2. FIG. 3 is a detailed perspective view around the tank 12.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a crawler hydraulic excavator will be described as an example of the construction machine 1. However, the construction machine 1 is not limited to a crawler hydraulic excavator, and an engine, a radiator, and air that has passed through the radiator are used. Any construction machine provided with a shroud for guiding to the engine room via a cooling fan can be widely applied to other construction machines such as a wheeled hydraulic excavator, a hydraulic crane, a wheel loader, and a tractor. In the following, the longitudinal direction of the hydraulic excavator 1 may be simply referred to as front and rear, the horizontal direction of the aircraft is simply left and right, and the vertical direction of the aircraft is also simply referred to as up and down. The forward direction in the direction shall be indicated. “Water injection” means a state, operation or operation in which cooling water is poured into the tank for replacement or replenishment of cooling water. “Water supply” means that the cooling water in the tank is supplied to the cooling water flow path. State, action or work to be performed.

  FIG. 1 is a side view of the excavator 1, and FIG. 2 is a top view of the upper swing body 4 in the excavator 1 (however, the working device 5 and the engine cover 17 are not shown). A crawler-type hydraulic excavator 1 as a construction machine 1 includes a lower traveling body 2 that can be self-propelled, an upper revolving body 4 that is turnably mounted on the lower traveling body 2 via a revolving device 3, and an upper revolving body. 4 is provided so as to be able to move up and down, and is roughly constituted by a work device 5 for performing excavation work of earth and sand. In the lower traveling body 2, the traveling motor 2A drives the footwear attached to the outer periphery thereof. The turning device 3 turns the upper turning body 4 with respect to the lower traveling body 2 by rotationally driving the turning motor 3A shown in FIG.

  The work device 5 is attached to the upper swing body 4 so as to be able to move up and down, an arm 5B attached to the tip of the boom 5A so as to be able to move up and down, and attached to the tip of the arm 5B so as to be rotatable. Bucket 5C. The boom 5A is lifted and lowered by the boom cylinder 5D, and the arm 5B is rotated by the arm cylinder 5E. Bucket 5C is rotated by bucket cylinder 5F. A control valve provided on the upper swing body 4 controls the travel motor 2A of the lower travel body 2, the swing motor 3A of the swing apparatus 3, and the hydraulic cylinders 5D, 5E, and 5F of the work device 5.

  A cab 7 is provided on the left front side of the revolving frame 6 constituting the lower part of the upper revolving structure 4. The cab 7 is provided with a driver's seat 71, a travel operation lever (not shown), a work operation lever (not shown) and the like so that an operator who operates the hydraulic excavator 1 can board. ing. A counterweight 8 is attached to the rear end of the revolving frame 6. The counterweight 8 is provided for weight balance with the work device 5 and protrudes so that the rear surface side is curved.

  As shown in FIG. 2, a machine room 25 that houses an engine 9 that is a drive source of the hydraulic excavator 1 is formed on the rear side of the revolving frame 6 and on the front side of the counterweight 8. The engine 9 is mounted on the revolving frame 6 in a horizontally placed state extending in the left-right direction. A control valve 60 (see FIG. 5) is mounted in front of the machine room 25 via a wall surface 19 (see FIG. 5).

  A driving pulley (not shown) is attached to the end of the output shaft of the engine 9. The rotation of the drive pulley is transmitted to a driven pulley (not shown) via an endless belt (V belt (not shown)), and the cooling fan 10 attached to the driven pulley rotates. The driving source of the cooling fan 10 is not limited to the engine 9 mechanically coupled thereto, and the cooling fan 10 may be rotationally driven by another driving source such as an electric motor.

  A hydraulic pump unit 22 including a plurality of hydraulic pumps is disposed on the opposite side of the cooling fan 10 to the engine 9, that is, on the right rear side of the hydraulic excavator 1. A hydraulic oil tank 21 and a fuel tank 20 are arranged side by side on the front side 22 of the hydraulic pump unit. The hydraulic oil tank 21 stores hydraulic oil for driving the lower traveling unit 2 and the work device 5. The hydraulic pump of the hydraulic pump unit 22 discharges the hydraulic oil in the hydraulic oil tank 21 to each hydraulic actuator as pressure oil. The hydraulic oil returned from each hydraulic actuator can be cooled by passing through an oil cooler 31 (described later).

  A turbocharger 9 </ b> A such as a turbocharger that increases the flow rate of intake air is provided above the front side of the engine 9 with the exhaust pipe 23 interposed therebetween. The engine 9 is supported on the revolving frame 6 in a vibration-proof state via a vibration-proof mount.

  On the left side of the engine 9, a heat exchanging device 33 including a radiator 30 that cools engine cooling water, an oil cooler 31 that cools hydraulic oil, and an intercooler 32 that cools air that the engine 9 sucks is disposed. Each of these coolers 30 to 32 is provided facing the cooling fan 10. In the example of FIG. 2, the oil cooler 31 is located on the foremost side, the radiator 30 behind it, and the intercooler 32 further behind it. Upper portions of the radiator 30, the oil cooler 31 and the intercooler 32 are covered with a heat exchanger cover 35.

  The engine 9, the heat exchange device 33, the hydraulic pump unit 22, and the like are arranged in a space (machine room 25) extending on the swivel frame 6 on the front side of the counterweight 8. The equipment provided on the revolving frame 6 such as the engine 9, the heat exchange device 33, the hydraulic pump unit 22, the hydraulic oil tank 21, and the fuel tank 20 is covered with a building cover 17 provided on the revolving frame 6. .

  The building cover 17 includes left side plates 17A and 17B which are positioned on the left side of the revolving frame 6 and extend in the vertical direction, right side plates 17C and 17D which are positioned on the right side of the revolving frame 5 and extend in the vertical direction, Upper surface plates 17E, 17F, and 17G extending in the horizontal direction between the upper ends of the side plates 17A to 17D, and engine covers 17H and 17I that cover the upper part of the machine room 25 behind the upper surface plates 17E, 17F, and 17G (FIG. 1, FIG. 3).

  The left side plate 17B is provided with an inflow port 72 (see FIGS. 1 and 3) composed of a plurality of vertically long holes through which air supplied as cooling air to the heat exchange device 30 flows. On the other hand, the right side plate 17D is provided with an outflow port 73 (see FIG. 3) comprising a plurality of vertically long holes for allowing the air (cooling air) that has passed through the engine 9 or the like to flow out.

  3 is a schematic cross-sectional view of the upper swing body 4 in the III-III cross section in FIG. 2, and FIG. 5 is a schematic cross-sectional view of the upper swing body 4 in the VV cross section in FIG. FIG. 2 is a detailed perspective view around the tank 12. The same parts as those in the previous figure may be denoted by the same reference numerals and description thereof may be omitted (the same applies to the subsequent figures).

  As shown in FIG. 3, in the machine room 25, a radiator 30 that cools the engine cooling water heated by the engine 9 by exchanging heat with air (cooling air), and air that is taken in via the radiator 30 ( The cooling fan 10 that sends cooling air) to the engine 9 and the engine 9 that is cooled by exchanging heat with the engine cooling water that is circulated and supplied to the water jacket 93 (see FIG. 4) are arranged in this order from left to right. Yes.

  A shroud 11 is provided between the radiator 30 and the engine 9 in the machine room 25 and is provided on the outer peripheral side of the cooling fan 10 and forms a passage for air taken into the engine 9 through the radiator 30. The engine-side side plate 11A of the shroud 11 is a substantially rectangular plate made of metal (however, as will be described later, the front side of the upper end of the side plate 11A extends higher than the rear side, so that an accurate rectangular shape is provided. Not a shape board.)

  A substantially circular opening 11C is provided at the center of the side plate 11A, and an annular ring member 11D is attached to the edge of the opening 11C so as to protrude toward the engine 9 side. A cooling fan 10 is fixed inside a substantially cylindrical space formed by the ring member 11D. The fixing position of the cooling fan 10 is not limited to the inside of the ring member 11D, and may be shifted left and right in FIG. 3 within a range in which the air in the shroud 11 can be supplied to the engine 9 side.

  An upper surface plate 11B is bridged between upper portions of the front side plate and the rear side plate of the shroud 11 that are arranged with a space in the front-rear direction and extend vertically in the left-right direction. The upper surface plate 11B is positioned at substantially the same height as the upper surface plate of the heat exchanger cover 35, and extends below the rectangular upper step portion 11b1 extending substantially horizontally in the front-rear direction, below the radiator upper hose 50 and the intercooler hose 56. The rectangular lower step portion 11b2 which is located at a lower height than the upper step portion 11b1 and extends substantially horizontally in the front-rear direction, and the rear end side of the upper step portion 11b1 and the front end side of the lower step portion 11b2 are connected to rise forward. It is comprised from the rectangular connection part 11b3 formed of the slope of a gradient. The upper step portion 11b1 is located in front of the connecting portion 11b3 and the lower step portion 11b2, and is located closest to the upper surface plates 17E and 17F (cab 7) among these three portions.

  In order to avoid the radiator upper hose 50 and the intercooler hose 56 protruding from the side plate 35B (see FIG. 6) of the heat exchanger cover 35 on the engine side (shroud side) of the heat exchanger cover 35, the lower step portion 11b2 The intercooler hose 56 is set at a position below the lower end.

  The upper step portion 11b1 is provided with a rectangular opening (shroud inspection window) 14A that is smaller than the upper step portion 11b1 and extends in the front-rear direction. A rectangular inspection window cover (opening / closing cover) 14B for closing the opening 14A is attached to the opening 14A so as to be able to open and close the opening 14A. The inspection window cover 14B of the present embodiment is attached so that the opening 14A can be opened and closed via a hinge (hinge part) 14C provided on the rear end side of the opening 14A. Accordingly, the inspection window cover 14B is supported so as to be rotatable with respect to the upper surface plate 11B (the shroud 11). In addition, a fixing tool 14D for fixing the inspection window cover 14B to the upper step portion 11b1 is provided at the free end (front end) of the inspection window cover 14B.

  When the inspection window cover 14B is opened, the opening 14A is exposed to the outside, and the inside of the shroud 11 can be accessed through the opening 14A. When, for example, a blower (blower) is inserted through the opening 14A and an air flow in the direction opposite to that during engine cooling is sent to the radiator 30, dirt and foreign matter adhering to the radiator core 30B can be removed.

  The shape of the opening 14A and the method of fixing the inspection window cover 14B to the upper step portion 11b1 are not limited to those described above, and the shape of the opening 14A is such that a cleaning tool such as a blower can be inserted into the shroud 11. The inspection window cover 14B may be fixed by any method as long as the inspection window cover 14B is detachable from the opening 14A.

  The upper end of the side plate 11A of the shroud 11 of the present embodiment is provided in accordance with the shape of the top plate 11B (that is, the shape of the upper step portion 11b1, the lower step portion 11b2, and the connecting portion 11b3), thereby forming a step. The front is higher than the rear.

  The radiator 30 is located at the upper end, and is provided with an upper tank 30A into which cooling water from the engine 9 flows via the radiator upper hose 50, a plurality of cooling water tubes connected to the lower portion of the upper tank 30A, and the plurality of cooling tubes. A radiator core 30B having a plurality of heat dissipating fins provided on the outer periphery of the thin water pipe, and a lower tank 30C that is located at the lower end and flows out to the engine 9 via the radiator lower hose 51 is cooled by the radiator core 30B. ing. The radiator 30 performs heat exchange between the cooling water introduced into the cooling water thin tube of the radiator core 30B and the cooling air taken in by the cooling fan 10, thereby dissipating the cooling water by radiating the heat of the cooling water into the cooling air. Cooling.

  A bracket (tank support member) 15 protruding substantially horizontally toward the engine 9 is attached to the upper portion of the side plate 11A of the shroud 11 via a bolt. The bracket 15 fixedly supports a tank (a reserve tank (also referred to as an expansion tank)) 12 in which coolant for replenishing (supplying) an engine cooling system including the radiator 30 and the engine 9 is stored. The upper end of the bracket 15 is located above the lower end of the upper tank 30A. The tank 12 is supported by a bracket 15 so that a horizontal surface (lower limit water level (described later)) of cooling water is formed above the upper end of the radiator 30, and is located adjacent to the shroud 11 and has an inspection window cover. It is arranged closer to the engine 9 than 14B.

  The bracket 15 is preferably fixed not only to the side plate 11A but also to at least one of the structural members constituting the machine room 25 in which the engine 9 is housed. For example, in FIGS. 5 and 6, the bracket 15 is supported from below by a support member 16 that is fixed to a wall surface (front wall surface) 19 that is disposed on the front side of the engine 9 and extends in the vertical direction and protrudes to the rear side. Thus, if the tank 12 (including cooling water) is fixedly supported via a plurality of members, the load of the tank 12 borne by one member can be reduced. Thereby, for example, since the load of the bracket 15 is reduced, the strength of the shroud 11 (side plate 11A) can be reduced, so that the cost of the shroud 11 can be reduced.

  The tank 12 is disposed adjacent to the side plate 11A so as to avoid the upper portion of the opening 14A provided in the upper surface plate 11B of the shroud 11. That is, in the plan view, the tank 12 is arranged so that the outline of the tank 12 and the outline of the opening 14A do not overlap. More specifically, the leftmost end of the tank 12 (the location closest to the radiator 30 in the tank 12 when viewed in a plan view) is the farthest right end of the opening portion 14A (when viewed in the plan view, the engine 9 is the most in the opening portion 14A). The tank 12 is fixed by the bracket 15 so as to be positioned closer to the engine 9 (right side) than the closer portion.

  An opening serving as a water supply port is provided on the bottom surface of the tank 12, and a makeup pipe (water supply pipe) 54 that is connected to the radiator lower hose 51 after extending downward substantially vertically is attached to the opening. Yes. Thereby, the cooling water in the tank 12 is supplied to the radiator lower hose 51 via the makeup pipe 54. In the tank 12, the height of the lower limit water level is set to a position higher than the uppermost part of the internal cavity of the upper tank 30A and higher than the uppermost part of the internal cavity formed by the cooling water flow path provided in the engine 9. ing. Normally, the upper end of the radiator 30 is higher than the upper end of the engine 9, so that the condition is satisfied if the lower limit water level is installed at a position higher than the uppermost part of the internal cavity of the radiator 30 (upper tank 30A). Will be.

  The makeup pipe 54 may be connected anywhere in the flow path from the radiator core 30B to the water pump 91, and may be connected to the radiator lower tank 30C or the water pump 91.

  An opening for injecting cooling water is provided on the upper surface of the tank 12, and a cap 12A is attached to the opening. The tank 12 is sealed by tightening the cap 12A after replenishing the cooling water. The upper limit water level of the tank 12 is determined so that an air layer is secured above the water layer in the tank 12. This air layer can stably maintain the pressure in the cooling water flow path. Moreover, it is preferable to provide the pressure valve (not shown) which can adjust the air pressure inside a tank in the upper part of the tank 12, or the cap 12A.

  The tank 12 has two openings. An air vent pipe 52 into which air extracted from the radiator 30 is introduced is attached to one of the openings, and air extracted from the cooling water flow path of the engine 9 is introduced into the other opening. An air vent pipe 53 is attached. In the example of FIG. 3, the air vent pipes 52 and 53 are connected to the side surface of the tank 12, but the connection position is not particularly limited, and may be connected to, for example, the upper surface or the lower surface of the tank 12.

  The other end of the air vent pipe 52 is connected to the upper end portion of the upper tank 30A of the radiator 30. When air is present in the radiator 30, the air together with the cooling water enters the tank 12 via the air vent pipe 52. Gas-liquid separation is introduced. As shown in FIG. 6, the radiator side of the air vent pipe 52 of the present embodiment is placed inside the heat exchanger cover 35 through a hole 35 </ b> A provided in the side plate 35 </ b> B on the engine 9 side of the heat exchanger cover 35. It is introduced and the end is connected to the upper tank 30A.

  As described above, it is preferable that the air vent pipe 52 is connected to the upper end portion (the highest portion) at which air easily accumulates in the upper tank 30A. However, since the cooling water always flows into the tank 12 due to the pressure difference generated in the cooling water flow path by the operation of the water pump 91, the air can be removed even if it is not the highest part. Therefore, the air vent pipe 52 may be connected to the side surface of the upper tank 30A.

  The other end of the air vent pipe 53 is connected to a portion where the coolant flow path provided in the engine 9 passes through a relatively higher position than the other portions. Thereby, when air exists in the cooling water flow path in the engine 9, the air is introduced into the tank 12 via the air vent pipe 53.

  Similarly to the air vent pipe 52, the air vent pipe 53 is preferably connected to the highest portion in the cooling water flow path of the engine 9, but may be connected to a side surface of the cooling water flow path. In addition, when the cooling water flow path of the engine 9 is arranged so as to draw a plurality of vertices (the heights of the vertices may be different or the same), any one of the plurality of vertices may be used. It is preferable to connect the air bleeding pipe 53 to one or each or the vicinity thereof. The engine cover 17H is configured to be rotatable about a rotation shaft (not shown) that is fixed above the heat exchange device 33 and extends in the front-rear direction, and can open and close the engine cover 17H. The engine cover 17 </ b> H is held at a position higher than the upper end of the tank 12. Although the upper surface of the engine cover 17H of the present embodiment extends substantially horizontally and has a uniform height, only the height of the upper portion of the tank 12 is made relatively higher than the other portions. Also good. For example, when such a cover shape (the shape of the cover 17Ha indicated by a one-dot chain line in FIG. 5) is adopted when the tank 12 is disposed at the front end in the machine room 25, a portion that is taller than before is used. Can be brought closer to the cab 7 (driver's seat 71), so that the rear view of the driver sitting on the driver's seat 71 can be ensured better than when the cover height is made uniform.

  An outline of the engine cooling system provided in the hydraulic excavator 1 according to the present embodiment will be described with reference to FIG. In addition, although the arrow in FIG. 4 has shown the distribution | circulation direction of cooling water (Including the case where air is contained in cooling water), the said arrow is not only the direction of the flow of cooling water but the flow path through which cooling water flows (Including piping and hoses).

  The engine cooling system shown in FIG. 4 includes a water pump 91, a thermostat 92, a water jacket 93, an ERG cooler 94, a radiator 30, and a tank 12.

  The water pump 91 is driven by the power of the engine 9 and circulates the cooling water by pushing out the cooling water from the thermostat 92 or the lower tank 30C and sending it to the water jacket 93 and the EGR cooler.

  The water jacket 93 is a water channel provided around a cylinder (not shown) of the engine 9, and the cooling water sent from the water pump 9 mainly exchanges heat with the engine 9 when passing through the water jacket 9. 9 is cooled.

  The EGR cooler 94 cools the engine exhaust by exchanging heat between the engine exhaust and the cooling water. The exhaust cooled here is mixed with the intake air and introduced into the cylinder again. The EGR cooler 94 and the related cooling system can be omitted.

  The thermostat 92 is a valve device that opens and closes the water channel according to the cooling water temperature, and opens when the cooling water temperature is equal to or higher than the valve opening temperature, whereby the cooling water is introduced into the radiator 30. On the other hand, the thermostat 92 when the temperature is lower than the valve opening temperature is closed, and the cooling water circulates without being introduced into the radiator 30. The illustrated thermostat 92 is installed in a flow path for cooling water to the outside (upper tank 30A) of the engine 9 (water jacket 93 and EGR cooler 94), but the inside of the engine 9 from the outside (lower tank 30C). You may install in the flow path into which cooling water enters (water pump 93).

  As described above, the engine-side end of the air vent pipe 53 is connected to a cooling water flow path configured in the engine 9, and the cooling water mixed with bubbles flows into the tank 12 through the flow path. Is done. In the example of FIG. 4, since the flow path connected to the outlet of the EGR cooler 94 passes through a high place in the engine, an air vent pipe 53 is connected to the flow path. Depending on the situation, it may be connected to a flow path from the water jacket 93 to the thermostat 92 or may be connected to another flow path.

  In the construction machine configured as described above, the lower limit water level of the tank 12 is set at a position higher than the place where the water level is highest in the radiator 30 and the cooling water flow path in the engine 9. Even if air is generated in the cooling water flow path, it can be introduced into the tank 12 via the air vent pipes 52 and 53 and separated from the cooling water. Further, since the tank 12 is arranged at a position adjacent to the side plate 11A of the shroud 11, the distance from the radiator 30, the engine 9 and the radiator lower hose 51 to the tank 12 can be shortened, and thereby the air vent pipes 52, 53 are provided. And the arrangement of the makeup pipe 54 becomes extremely easy. Further, when the tank 12 is arranged in this manner, the makeup pipe 54 can be extended substantially vertically from the bottom surface of the tank 12 to be connected to the radiator lower hose 51, so that the water supply from the tank 12 to the radiator lower hose 51 when cooling water is supplied is extremely smooth. To be done. Furthermore, since there is no other device including the tank 12 above the opening 14A in the upper surface plate 11B of the shroud 11, it is extremely easy to clean the radiator by inserting a blower from the opening 14A. Therefore, according to the present embodiment, air can be vented from the cooling water flow path provided in the radiator 30 and the engine 9 without impairing the water injection performance to the engine cooling system and the cleaning performance of the radiator 30.

  When water is supplied to the tank 12 or when the radiator 30 is cleaned, the worker works while being placed on the top plates 17E and 17F. Therefore, as described above, the opening portion 14A and the inspection window cover 14B are formed in the upper step portion 11b1. If it is provided, the worker can easily access the opening 14A and the inspection window cover 14B. Further, in the present embodiment, since the hinge 14C is provided on the rear end side of the opening 14A, the free end that the worker grips when opening and closing the inspection window cover 14B can be arranged on the upper surface plates 17E and 17F side. The opening / closing operation of the inspection window cover 14B is facilitated. Furthermore, when the hinge 14C is provided on the rear end side of the opening 14A, the free end of the inspection window cover 14B rotated around the hinge 14C is positioned rearward when the opening 14A is opened. The inspection window cover 14B does not interfere with the cleaning of the radiator 30.

  Moreover, it is preferable to set the height of the upper stage part 11b1 to a position above the upper ends of the radiator upper hose 50, the intercooler hose 56, and the air vent pipe 52 as in the present embodiment. In this way, even if the inspection window cover 14B is fully opened, before the upper surface of the inspection window cover 14B comes into contact with the radiator upper hose 50, the intercooler hose 56, or the air bleeding pipe 52, a part of the upper step portion 11b1 or after this Since it contacts a fixing tool such as a bolt protruding upward, it is possible to prevent the upper surface of the inspection window cover 14B from coming into contact with the radiator upper hose 50, the intercooler hose 56 or the air vent pipe 52 and damaging it.

  In addition, regardless of the height relationship between the upper step portion 11b1 and the lower step portion 11b2, during the cleaning work, by spanning a support rod (replacement rod) between the upper step portion 11b1 or its surrounding members and the inspection window cover 14B, It is preferable that the inspection window cover 14B is held in a state that does not interfere with cleaning, and the free end of the inspection window cover 14B is held at a position where it can be easily gripped after the cleaning operation is completed.

  In the above embodiment, the radiator upper hose 50, the intercooler hose 56, and the air vent pipe 52 protrude from the side plate 35B on the engine side (shroud side) of the heat exchanger cover 35 to the engine 9 side. However, in addition to this, a hydraulic oil pipe or other pipe for supplying the hydraulic oil to the oil cooler 31 may protrude. In addition, at least one of the hydraulic oil pipe, the radiator upper hose 50, the intercooler hose 56, and the air vent pipe 52 may protrude from the side plate 35B on the engine side of the heat exchanger cover 35. However, in any case, the present invention can be applied, and in any case, contact between the upper surface of the inspection window cover 14B and each pipe can be avoided.

  By the way, although the upper surface plate 11B of the present embodiment has different heights in the upper step portion 11b1 and the lower step portion 11b2 in order to facilitate access to the inspection window cover 14B provided in the upper step portion 11b1, the upper step portion 11b1. May be lowered to the height of the lower step portion 11b2 to make the upper surface plate 11B horizontal. However, when the bracket 15 is fixed to the side plate 11A at a position higher than the height of the lower step portion 11b2 for the purpose of holding the lower end of the tank 12 above the radiator 30 as in the above embodiment, the upper step Even when the portion 11b1 is lowered to the height of the lower step portion 11b2, the shape of the side plate 11A needs to be left as it is (that is, the upper end of the side plate 11A needs to have a stepped shape in which the front is higher than the rear. is there).

  In the above example, the side plate 11A is extended to the upper surface of the heat exchanger cover 35, and the bracket 15 is attached thereto to support the tank 12. However, the upper surface plate 11B of the shroud 11 and the upper end portion of the side plate 11A are If it is lower than the upper surface of the heat exchanger cover 35, a bracket taller than that described above may be attached to the side plate 11A, and the tank 12 may be installed at a position that satisfies the same conditions as described above. The bracket 15 is not limited to the side plate 11 </ b> A (the shroud 11), but may be a partition wall that is provided substantially vertically before and after the engine 9 and demarcates the machine room 25 or a similar member (structural member).

  In addition, this invention is not limited to said embodiment, The various modifications within the range which does not deviate from the summary are included. For example, the present invention is not limited to the one having all the configurations described in the above embodiment, and includes a configuration in which a part of the configuration is deleted. In addition, part of the configuration according to one embodiment can be added to or replaced with the configuration according to another embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Hydraulic excavator (construction machine), 2 ... Lower traveling body, 4 ... Upper turning body, 5 ... Working apparatus, 6 ... Turning frame, 7 ... Cab, 9 ... Engine, 10 ... Cooling fan, 11 ... Shroud, 11A ... Shroud side plate (engine side surface), 11B ... shroud top plate, 11b1 ... upper step, 11b2 ... lower step, 11b3 ... connecting portion, 12 ... reserve tank (tank), 14A ... opening (shroud inspection window) , 14B ... Inspection window cover (cover), 14C ... Hinge (hinge part), 15 ... Bracket, 16 ... Support member, 17 ... Building cover, 19 ... Front wall surface (structural member), 25 ... Machine room, 30 ... Radiator, 30A ... Upper tank, 30B ... Radiator core, 30C ... Lower tank, 32 ... Intercooler, 33 ... Heat exchange device, 50 ... Radiator upper ho , 51 ... radiator lower hose, 52 ... air vent pipe (radiator side), 53 ... air vent pipe (engine side), 54 ... Makeup pipe (water supply pipe)

Claims (3)

Engine,
A radiator that cools and cools the cooling water heated by the engine;
A cooling fan that is arranged between the radiator and the engine and sends air taken in via the radiator to the engine;
In a construction machine comprising a shroud provided on the outer peripheral side of the cooling fan and forming a passage of air taken in via the radiator,
Storing the coolant supplied to the radiator and the engine, and a tank disposed above the upper end of the radiator;
A cover attached to the opening provided on the upper surface of the shroud so as to be openable and closable,
The construction machine according to claim 1, wherein the tank is disposed at a position adjacent to the shroud and closer to the engine than the cover. The construction machine according to claim 1,
A water supply pipe for supplying cooling water to a cooling water flow path connecting the radiator and the engine is connected to the bottom surface of the tank,
A construction machine, wherein the tank is connected to an air vent pipe that opens into the tank and into which air extracted from the radiator or the engine is introduced. The construction machine according to claim 1,
The upper surface of the shroud includes an upper step portion to which the cover is connected via the hinge portion, a lower step portion positioned below the upper step portion, and a connecting portion that connects the upper step portion and the lower step portion,
A construction machine, wherein an air vent pipe for extracting air from the radiator is disposed between the height of the upper stage part and the height of the lower stage part.

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